Dispensers for delivering a beneficial agent to an environment of use are known to the dispensing art. For example, U.S. Pat. No. 3,760,984 issued to patentee Theeuwes discloses a dispenser consisting of a heat shrinkable container carrying on its outer surface an osmotic solute and a distant layer of a polymer permeable to fluid. The dispenser has a plug for filling the container. The dispenser is powered by fluid being imbibed into the dispenser, wherein it dissolves the solute, thereby forming a solution that exerts pressure against the shrinkable container, causing it to shrink and deliver agent from the dispenser. In U.S. Pat. No. 3,865,108 patentee Hartop discloses a dispenser consisting of an inner collapsible tube containing a medicament disposed in a base member formed of a swellable material. The dispenser delivers the medicament by the base and parts absorbing fluid from the environment, thereby expanding and squeezing the collapsible tube causing the medicine to be expelled from the tube. In U.S. Pat. No. 3,971,376 patentee Wichterle discloses a dispenser consisting of a capsule having unitary walls formed of a cross-linked gel that is swellable in fluids. A textile fabric is imbedded in the material for imparting strength and minimizing problems due to poor mechanical properties associated with the material that show themselves during fluid uptake used to power the dispenser. In U.S. Pat. No. 3,987,790, patentees Eckenhoff, et al., disclose an improvement in an osmotic dispenser consisting of a conduit for filling a bag in the dispenser. The dispenser is powered by an osmotically effective solute imbibing fluid into the dispenser, which imbibed fluid generates hydraulic pressure that is applied against the bag, causing it to squeeze inward1y forcing agent from the dispenser. In U.S. Pat. No. 3,995,631, patentees Higuchi, et al, disclose a bag bearing on its outer surface a layer of an osmotic solute, and a distant wall formed of a material having part controlled permeability to fluid. In operation. a solution is formed of the solute, which solution squeezes against the bag thereby causing delivery of the agent from the bag. In U.S. Pat. No. 4,320,758 patentees Eckenhoff, et al., disclose a dispenser consisting of a flexible bag, a sleeve made of a dispersion of an osmotically effective solute in a soluble polymer, and an outer wall permeable to fluid. The dispenser delivers drug by the sleeve imbibing water into the space between the outer wall and the bag, thereby exerting hydraulic pressure on the bag, which pressure causes the bag to be squeezed and delivers drug from the bag. U.S. Pat. No. 4,350,271 discloses a fluid dispenser that operates by absorbing water into a composition that expands against a lipophilic fluid that is dispensed via an outlet.
While the above dispensers are useful for delivering numerous agents to the environment of use, and while the dispensers represent a commercial advancement in the dispensing art, it will be appreciated by those skilled in the art that there are instances where a dispenser made with an inventively novel improvement would also enjoy wide commercial use and application in the dispensing art. For example, if a dispenser is provided having an initial internal capsule arrangement that makes the manufacture of the dispenser easier and more efficient at a reduced cost, and if the dispenser is made without a flexible bag and without a fabric member, thereby providing an improvement in the dispenser by reducing the number of steps and parts needed to make the dispenser, such a dispenser would have immediate acceptance, and it would also represent a major advancement in the art. Likewise, if a dispenser is provided that overcomes the prior art dispenser limitation of delivering agents only in solution or suspension forms, by the dispenser now delivering agents that are soluble or insoluble in fluid, semi-solid or like forms, such a dispenser would enjoy instant appreciation and also represent a valuable contribution in the fields of science, medicine and commerce.